Lay citizens participate as decision makers in the legal systems of many countries. This review describes the different approaches that countries employ to integrate lay decision makers, contrasting in particular the use of juries composed of all citizens with mixed decision-making bodies of lay and law-trained judges. The review discusses research on the benefits and drawbacks of lay legal decision making as well as international support for the use of ordinary citizens as legal decision makers, with an eye to explaining a recent increase in new jury systems around the world. The review calls for more comparative work on diverse approaches to lay participation, examining how different methods of including lay participation promote or detract from fact finding, legal consciousness, civic engagement, and citizen power.